Heating system



,7 Feb. 9, 1943. a s. RUSSEL HEATING SYSTEM Filed May 11, 1939" R Mn mNW N O m m 001 Patented Feb. 9, 1943 HEATING SYSTEM Philip S. Russel,Detroit, Mich, assignor to Detroit Lubricator Company, Detroit, Mich, acorporation of Michigan Application May 11, 1939, Serial No. 273,140

Claims.

My invention relates to new and useful improvements in heating systemsand more particularly to means for controlling a medium supplied to aregion or space to be heated.

An object of my invention is to provide means for regulating theoperation of a burner for heating the medium.

Another object is to provide means to supply the medium irrespective ofoperation of the burner.

Another object is to control the operation of the burner in accordancewith the temperature of the medium to be heated.

The invention consists in the novel system and the combination andrelation of control elements comprising the same, to be more fullydescribed hereinafter and the novelty of which will be particularlypointed out and distinctly claimed.

In the accompanying drawing, to be taken as a part of thisspecification, I have fully and clearly illustrated a preferredembodiment of my invention, in which drawing The figure is adiagrammatic View illustrating a heating system embodying my invention.

Referring to the drawing by characters of reference, I designatesgenerally a heating apparatus which may be a hot air furnace or a waterheater or boiler having an outlet flue 2 for the products of combustion,a conduit or pipe 3 for supplying to the space or region to be heatedthe medium such as air or water to be heated by the apparatus, and areturn pipe or conduit 4 for returning the heated medium after use tothe heating apparatus. The apparatus I contains in the combustionchamber a liquid fuel burner 5 supplied with oil through a conduit orpipe 6 leading from a constant level chamber or reservoir 7 which may befed from any suitable source of supply and therefore the burner is ofthe gravity fed type and may be of the gravity fed pot type. The burner5 is supplied with air for combustion through a duct 1 having an airsupply fan or blower 8 driven by an electric motor 9. The medium to beheated is supplied to the apparatus I and to the space to be heated byan electrically driven circulator Hi preferably positioned in the returnconduit 4. Discharge of fuel to the burner 5 and from chamber 7 iscontrolled by a valve means it which is normally positioned or held. bya cooperable stop member l2 in a position to supply sufficient oil tomaintain a pilot flame in the burner. The valve means ll preferablycomprises a reciprocal valve movable toward open position automaticallyby an electrically heated thermostatic actuator l3 which is the mediumfire actuator, and also movable further toward open positionautomatically by an electrically heated thermostatic actuator M which isthe high fire actuator. The actuator l3 comprises a bimetal leaf orelement 15 fixed at one end and having its other end extending into aslot IS in the stem of valve 1 l for engagement of the upper end of theslot to lift or open the valve.- The actuator It also has an electricheater or resistance element IT for heating the bimetal element IE tocause it to warp or band i upward at its free end for opening the valveH. The actuator It comprises a bimetal strip or element l8 to be heatedby an electric heater or re sistance element [9. The bimetal element Itis fixed at one end and has its other end extending into a slot 20 inthe stem of valve H such that upon upward warping of the free end ofbimetal element It when heated by resistance element I9 it will engagethe upper end wall of slot 20 to lift valve ll toward open position. Astop 2| which may be adjustable is provided to limit the openingmovement of the valve H by engagement of the end of the valve therewith.The motor 9 is controlled by a switch 22 which may be of the mercurytube type carried by a lever 23 which is tiltable to close the motorcircuit by an electrically heated thermostatic actuator 24. Thisactuator 24 comprises a bimetal strip or element 25 fixed at one end andhaving its free end engageable with the lever 23, the strip being heatedby an electric heater or resistance element 26. Connected to theterminals of the motor 9 are lead wires 27, 28 of which wire 21 isconnected to a main line wire 29 and wire 28 is connected to oneterminal of the switch 22. From the other terminal of the switch 22 alead wire 39 extends and is connected to the other main line wire 3!.Connected to the lead wires 21 and 30 are branch lead wires 32, 33respectively of which wire 32 is connected to one terminal of thecirculator l0 and the wire 33 is connected to one terminal of a normallyopen relay switch 34, the other terminal of the relay switch beingconnected by a lead wire 35 to the remaining terminal of the circulatorH3.

Positioned in the space or region to be heated there is a temperatureresponsive switch means 36 having electric switches 37!, 33 operated byand preferably carried by a thermostatic bimetal actuator 39. One of theterminals of switch 3'! is supported from the actuator 39 by a leafspring 40 so that upon closure of switch 31 the actuator 39 can havecontinued movement before closing switch 38. The movable terminals ofswitches 31, 38 are electrically connected to one terminal of thesecondary 4| of a transformer 42 as by a lead wire 43 connected to theactuator 39. The primary 44 of transformer 42 is electrically connectedto the main line wires 29 and 3|. Extending from the fixed contact ofswitch 31 is a lead wire 45 having branch wires 48, 41 leadingrespectively to the coil of the relay switch 34 and to one end of themedium fire resistance element H. The other terminal of the relay switchcoil is connected by a lead wire 48 to the remaining terminal of thetransformer secondary 4|. Extending from the remaining terminal ofresistance element l1 and from one terminal of the.

high fire resistance element l9 are lead wires 49, 50 respectively whichare joined to a common lead wire 5|. Responsive to the temperature ofthe medium heated by burner 5 there is a thermostatic switch 52 which isin closed circuit position at all temperatures below a predetermineddesired high temperature which, for example, may be 200 F., the leadwire 5| being connected to one terminal of this switch 52. The otherterminal of switch 52 is connected by a lead wire 53 connected to andthrough the lead wire 48 and to the transformer secondary 4| The fixedcontact of the thermostatic switch 38 is connected by a lead wire 54 toone terminal of the resistance element 26 which has its other terminalconnected by a lead wire 55 to the remaining terminal of the high fireresistance element l9.

The operation of the system is as follows: The stop member I2 isadjusted to position valve H to maintain a pilot flame in burner -5 andmay be such that when the medium to be heated is water, the pilot flamewill be sufiiciently high to maintain the water hot enough for heatingof a domestic hot water supply. Such a pilot flame will also maintain areserve supply of hot water or of heated air for immediate dischargeupon operation of the circulator l so that heated medium will beimmediately supplied to the space to be heated upon a demand for heat.With the burner operating at pilot flame and the transformer primary 44energized, then if the temperature in the space to be heated drops to apredetermined temperature, say 70 F., the thermostatic actuator 39 willoperate to close switch 31 which will complete the transformer secondarycircuit, with current flowing from the secondary 4| through lead wire43, switch 31, lead wires 45 and 46 to the coil of relay switch 34 andthence via lead wire 48 back to the transformer secondary 4|. The relayswitch 34 willtherefore be closed and start operation of the- Closure ofswitch 31 will also, if

the circuit through lead wires 45 and 41 to the medium fire heatingelement H from which current flows via lead wires 49 and to switch 52and thence via lead wires 53 and 48 back to the transformer secondary 4|Heat imparted to the bimetal element l5 by resistance element will causethe element I5 to warp or bend upward, thereby lifting the valve II toan intermediate open position which will supply sufficient fuel throughpipe 9 to the burner 5 to provide for a medium fire. Should thetemperature of the heated medium rise above the temperature at whichswitch 52 is set to operate, then the circuit to resistance element I!will be broken at switch 52 without affecting continued operation of thecirculator l0 which is under the sole control of the thermostatic switch31. If the temperature in the space to be heated continues to fallirrespective of medium fire operation such that the actuator 39 closesswitch 38, say at 68 F., then the resistance elements 26 and I9 will beenergized provided the temperature of the medium to be heated has notrisen sufficiently to open switch 52. The elements 26 and I9 are in aseries circuit which may be traced as follows: from the transformersecondary 4| through lead wire 43, actuator 39, switch 38, lead wire 54to element 26, lead wire 55 to element I9 and via leadwires 50 and 5| toswitch 52 and from switch 52 via lead wires 53 and 48 back to thetransformer secondary 4|. l'he bimetal switch actuator 25 and thebimetal valve actuator 8 will be simultaneously heated but due to thelost motion of actuator l8 before it engages the end wall of slot tofurther open valve I. the switch 22 will be closed, thereby closing thecircuit to motor 9 and starting operation of fan 8 to supply combustionair to the burner 5. The actuator |8 will continue to bend or warpupward after engagement with the end wall slot of 28 and will move thevalve to further open position until it engages maximum limit stopmember 2| which determines the maximum open position of vlave and themaximum high fire at the burner 5. As the temperature in the space to beheated warms up, the actuator 39 will first open switch 38 when thetemperature exceeds say 68 F., thereby deenergizing the resistanceelements of the heat motor actuators 24 and I4. Cooling of the actuator24 will open switch 22, thereby breaking the circuit to the motor 9 andstopping operation of fan 8. Cooling of the actuator 4 will permit valveII to move downward until it is supported by the bimetal element |5 inintermediate open position so that; the burner 5 will continue operationwith a medium flame or fire. When the temperature responsive means 36becomes completely satisfied, say at 70 F., the actuator 39 will openswitch 31, thereby deenergizing the relay switch 34 to stop thecirculator l0 and also deenergizing the medium fire heating element I!so that bimetal element I5 will cool and permit valve II to movedownward until stop members l2 are in engagement providing for pilotfire operation of the burner 5.

From the foregoing it will be noted that I have provided a system inwhich safety means in the form of switch 52 is provided for controllingoperation of the burner and stopping regulation of the burner by thespace responsive means while permitting control by the space responsivemeans of the supply of heated medium to the space to be heated.

What I claim and desire to secure by Letters Patent of the United Statesis:

1. A heating system comprising a heating apparatus having a gravity typeliquid fuel burner, controllable means for supplying fuel to saidburner, electrically controlled means for operating said controllablemeans to supply fuel for a medium fire, means to supply air to saidburner for said medium fire, electrically controlled means for operatingsaid controllable means to supply fuel for a high fire, means responsiveto temperature in a space to be heated by said apparatus and operableupon a predetermined low temperature to energize said first-namedcontrolled means, and electrically operated means to increase the supplyof combustion air through said supply means to said burner for said highfire, said responsive means acting upon occurrence of a temperaturebelow said low temperature to energize said second-named controlledmeans and said electrically operated air supply means, said last-namedelectrically operated air supply means being so constructed and arrangedrelative to said second-named controlled means that said air supplymeans is energized and supplies said increased air prior to supply offuel for the high fire by said second-named controlled means.

2. A heating system comprising a heating apparatus having a liquid fuelburner, a constant level chamber for supplying fuel to said burner, avalve controlling the discharge of fuel from said chamber and normallyin a position to supply fuel for pilot flame operation, an electricallyheated thermostatic actuator operable to move said valve to supply fuelfor a medium fire, an electrically heated thermostatic actuator to movesaid valve to supply fuel for a high fire, electrically operated meansto supply combustion air to said burner, electrically operated mean tosupply the medium heated by said burner to the space to be heated, meansresponsive to the temperature of the heated medium and operable uponoccurrence of a high temperature to break the circuits of saidfirst-named and said second-named thermostatic actuator and ineffectiveto control said secondnamed electrically operated means, and meansresponsive to temperature in the space heated by the heated medium andcontrolling the circuits of said first-named and said second-namedthermostatic actuator and of said first-named and said second-namedelectrically operated means.

3. A heating system comprising a heating apparatus having a liquid fuelburner, a constant level chamber to supply fuel to said burner, a

valve controlling the discharge of fuel from said chamber, anelectrically heated thermostatic actuator operable to move said valve tosupply fuel for a medium fire, an electrically heated thermostaticactuator operable to move said valve to supply fuel for a high fire, athermostatic switch responsive to the temperature of the medium heatedby said burner and operable upon occurrence of a high temperature tobreak the circuits of said actuators, an electrically driven fan forsupplying combustion air to said burner, a thermostatic switchcontrolling the circuit of said fan, an electric heater for saidlast-named switch, electrically operated means to supply the heatedmedium to a space to be heated, an electric switch controlling thecircuit of said first-named actuator and of said electrically operatedmedium supply means, an electric switch controlling the circuit of saidsecond-named actuator and of said electric heater, and thermostaticmeans responsive to temperature in the space heated by the medium andoperable at a predetermined low temperature to close said first-namedelectric switch and at a temperature below said predeterminedtemperature to close said second-named electric switch.

4. A heating system comprising a heating apparatus having a gravity typeliquid fuel burner, controllable means for supplying fuel to saidburner, electrically controlled means for operating said controllablemeans to supply fuel for a medium fire, electrically controlled meansfor operating said controllable means to supply fuel for a high fire,lost motion means interconnecting said last-named means and saidcontrollable means, means responsive to temperature in a space to beheated by said apparatus and operable upon a predetermined lowtemperature to energize said first-named controlled means, andelectrically operated means to supply combustion air to said burner,said responsive means acting upon occurrence of a temperature below saidlow temperature to energize said second-named controlled means and saidelectrically operated air supply means, said lost motion means beingoperable to provide a time delay thereby to insure that said air supplymeans supplies said high fire air to said burner prior to the supply offuel for the high fire by said second-named controlled means.

5. A heating system comprising a heating apparatus having a liquid fuelburner, means controlling the floW of fuel to said burner, meansnormally supplying fuel for pilot flame operation of the apparatus, anelectrically heated thermostatic actuator operable to move saidcontrollin means to supply fuel for a medium fire, an electricallyheated thermostatic actuator to move said controlling means to supplyfuel for a high fire, electrically operated means to supply combustionair to said burner, electrically operated means to supply the mediumheated by said burner to the space to be heated, means responsive to thetemperature of the heated medium and operable upon occurrence of a hightemperature to break the circuits of said first-named and saidsecondnamed thermostatic actuator and ineffectiv to control saidsecond-named electrically operated means, and means responsive totemperature in the space heated by the heated medium and controlling thecircuits of said first-named and said second-named thermostatic actuatorand of said first-named and said second-named electrically operatedmeans.

PHILIP S. RUSSEL.

